1. Field of the Invention
An aspect of the present invention relates to a film formation device, a substrate processing device, and a film formation method.
2. Description of the Related Art
For example, an Atomic Layer Deposition (ALD) method using a device as described in Japanese Patent Application Publication No. 2010-239102 has been known for a method for film-forming a thin film, for example, a silicon oxide (SiO2) film or the like, on a substrate such as a semiconductor wafer (that will be referred to as a “wafer” below). In this device, 5 wafers are arranged on a rotating table in a direction along a periphery thereof and a plurality of gas nozzles are arranged at an upper side of this rotating table. Then, a plurality of kinds of reactive gasses that react with one another are sequentially supplied onto each revolving wafer to laminate reaction products.
In order to conduct plasma modification on each reaction product laminated on a wafer in such an ALD method, a device has been known that provides a member for conducting plasma modification at a position separated from a gas nozzle in a peripheral direction like Japanese Patent Application Publication No. 2011-040574. However, in a case where a recess, such as a hole or a groove (trench), having an aspect ratio, for example, greater than tens to hundreds, is formed on a surface of a wafer, a degree of modification in a direction of a depth of this recess may be dispersed.
That is, as a recess with a greater aspect ratio is thus formed, it may be difficult for plasma (in more detail, an argon ion) to approach the recess. Furthermore, a plasma modification process and a film formation process are conducted in a vacuum chamber, and hence, a process pressure in such a vacuum chamber is a pressure that is higher than that of a vacuum atmosphere that could maintain an activity of plasma better. Therefore, when plasma contacts an inner wall surface of a recess, such plasma is readily deactivated, and hence, a degree of modification in a direction of a depth of the recess is readily dispersed thereby. Furthermore, even for a wafer with no recess formed thereon, it may be necessary to form a higher density plasma near the wafer in order to conduct a modification process during one revolution of a rotating table, that is, conduct a modification better in a narrower area between mutually adjacent gas nozzles.
Japanese Patent Application Publication No. 8-213378 describes a device for applying a bias voltage to a lower electrode but does not describe a technique for revolving a wafer by a rotating table.